Timber roof structures covering traditional masonry buildings strongly influence the seismic response of the whole building system. In the seismic strengthening of these structures, their replacement or their reinforcement with massive interventions has been performed in the past, at times with adverse results. In Italy, the national design code now indicates that less invasive strengthening techniques appear as a better option and should be applied. In this perspective, a methodology for assessing the seismic vulnerability associated to timber roof structures has been developed by the authors. This necessarily includes the evaluation of previous interventions when present, as part of the assessment of the present state of the structure. This work focuses particularly on the refinement and calibration of this point in the assessment procedure. To this purpose, a set of structures has been examined and studied by numerical modeling, providing some guidance in the exam of similar cases.

Timber roof structures covering traditional masonry buildings strongly influence the seismic response of the whole building system. In the seismic strengthening of these structures, their replacement or their reinforcement with massive interventions has been performed in the past, at times with adverse results. In Italy, the national design code now indicates that less invasive strengthening techniques appear as a better option and should be applied. In this perspective, a methodology for assessing the seismic vulnerability associated to timber roof structures has been developed by the authors. This necessarily includes the evaluation of previous interventions when present, as part of the assessment of the present state of the structure. This work focuses particularly on the refinement and calibration of this point in the assessment procedure. To this purpose, a set of structures has been examined and studied by numerical modeling, providing some guidance in the exam of similar cases.